1. Field of the Invention
The present invention concerns a control and protection module for a low voltage electric switch device, such as a contactor-breaker. This control and protection module governs the control of an electromagnet and tripping device which are capable of opening and closing the power poles of the electric switch device. The invention also concerns an electric switch device that may be connected to such a control and protection module.
2. Description of Related Art
A contactor-breaker is a multipolar electric device used for controlling and protecting an electric charge such as a motor. The contactor-breaker can control the feed and cut-off of the power leads linked to the charge, by means of a control electromagnet attached to the “contactor” part. By way of an electromagnetic trip mechanism, it also cuts off the power leads automatically when an electrical fault occurs in at least one of the leads, such as a thermal overload, a magnetic overload or a short circuit.
In such a device, the power poles have stationary and moving contacts within the cut-off areas. The control electromagnet prompts a multipolar component to act upon the moving contacts in order open or break the power leads in response in response to a command from a control model. The trip device also prompts the multipolar component to act upon the moving contacts in order to open the power poles in response to the detection of an electric fault coming from a protection device. The trip device can be reset by a manual control component that can also prompt the multipolar component to ensure the opening of the moving contacts.
The document EP 366 519 describes such a contactor breaker of the type referred to above. The protection device is essentially mechanical, because it needs to work with a large number of devices and a wide range of voltages and power currents. In document FR 2 759 489, the electromagnet of a contactor-breaker carries out the switching of the contacts in both contactor and breaker mode. The hybrid way in which the electromagnet functions and the high speed of control necessary in breaker mode is problematic.
The document WO 01/27958 describes a contactor-breaker whose power leads, fixed and moving contacts, control electromagnet and the trip device are housed in a connector base of the device. The connector base is connected to an electronic control and protection device which has the advantage of being a detachable module interchangeably linked to the connector base. This arrangement allows, for the same base, to receive different ratings of protection modules, hence reducing the different combinations necessary for covering a whole range of products. Furthermore, this arrangement allows the user to customize the contactor-breaker at the last moment, after cabling the power section.
However, in this type of switch, operational safety must be permanently guaranteed by the different control and protection units. This is why the main aim of this invention is to increase the operational safety of a contactor-breaker by putting in place servo-devices between the control of the electromagnet and the control of the trip magnet offering a redundancy of safety functions because of the use of electronic, central processing means for driving and controlling both the electromagnet and the trip device.